207 



U. S. DEPARTMENT OF AGRICULTURE. 

BUREAU OF PLANT INDUSTRY— BULLETIN NO. 124. 

B. T. GAhLOWAWChief of Bureau. 



THE PItlCKLY PEAR AS A FARM ' 



DAVID GRIFFITHS, 
Assistant A(H{Ioui-ti'ri8t. Fakm MANAGEMEisfT Investigations. 



Issued FF.niaiAKv 1!>, UM»S. 




WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 

1908. 



%m0 




2.QJ 



U. S. DEPARTMENT OF AGRICULTURE. 

It 

BUREAU OF PLANT INDUSTRY— BULLETIN NO. 124. 

B. T. a ALLOW AY, Chief 0/ Bureau. 



THE PRICKLY PEAR AS A FARM CROP. 



DAVID GRIFFITHS, 
Assistant Agkiculturist, Farm Manacjement IxvESTioATiONa. 



Issued Feukuary lU, 1908. 




WASHINGTON: 
government printing office. 

1908. 



BUREAU OF PLANT INDUSTRY. 

Pathologist and Phi/sioJoyist, and Chief of Bureau, Beverly T. Galloway. 

Pathologist and Phiisiologist, and Assistant Chief of Bureau, Albert F. Woods. 

Lahoratorii of Plant Pathology, Erwin F. Smith, Pathologist in Charge. 

Investigations of Diseases of Fruits, Merton B. Waite. Pathologist in Charge. 

Laboratory of Forest Pathology, Haven Metcalf, Pathologist in Charge. 

Truck Crop Diseases and Plant Disease fiurvey, William A. Orton, Pathologist in Charge. 

Plant Life History Investigations, Walter T. Swingle, Physiologist in Charge. 

CgtTon Breeding Investigations, Archibald D. Shamel and Daniel N. Shoemaker, Physiolo- 
gists in Charge. 

Tobacco Investigations. Archibald D. Shamel, Wightman W. Garner, and Ernest H. 
Mathewson, in Charge. 

Corn Investigations, Charles P. Hartley. Physiologist in Charge. 

Alkali and Drought Resistant Plant Breeding Investigations, Thomas H. Kearney, Physi- 
ologist in Charge. 

Soil Bacteriology and Water Purification Investigations, Karl F. Kellerman, Physiologist 
in Charge. 

Bionomic Investigations of Tropical and Subtropical Plants, Orator F. Cook. Bionomfst 
in Charge. 

Drug and Poisonous Plant Investigations and Tea Culture Investigations, Rodney H. 
True, Physiologist in Charge. 

Physical Laboratory, Lyman J. Briggs, Physicist in Charge. 

Crop. Technology and Fiber Plant Investigations, Nathan A. Cobb, Crop Technologist in 
Charge. 

Taxonomic and Range Investigations, Frederick V. Coville, Botanist in Charge. 

Farm Management Investigations, William J. Spillman, Agriculturist in Charge. 

Grain Investigations, ^lark A. Carleton, Cerealist in Charge. 

Arlington Erperimcntal Farm, Lee C. Corbett, Horticulturist in Charge. 

Vegetable Testing Gardens, William W. Tracy, sr., Superintendent. 

Sugar-Beet Investigations, Charles O. Townsend, Pathologist in Charge. 

Western Agricultural Extension Investigations, Carl S. Scofleld, Agriculturist in Charge. 

Dry-Land Agriculture Investigations, E. Channing Chilcott, Agriculturist in Charge. 

Pomological Collections, Gustavus B. Brackett, Pomologist in Charge. 

Field Investigations in Pomology, William A. Taylor and G. Harold I'ovvell, I'omologists 
in Charge. 

Experimental Gardens and Grounds, Edward M. Byrnes, Superintendent. 

Seed and Plant Introduction, David Fairchild, Agricultural Explorer in Charge. 

Forage Crop Investigations, Charles V. Piper, Agrostologist in Charge. 

Seed Laboratory, Edgar Brown, Botanist in Charge. 

Grain Standardization, John D. Shanahan, Expert in Charge. 

Subtropical Laboratory and Garden, Miami, Fla., Ernst A. Bessey, Pathologist in Charge. 

Plant Introduction Garden, Chico, Cal., August Mayer, Expert in Charge. 

South Texas Garden, Broansville, Tex., Edward C. Green, Pomologist in Charge. 

Cotton Culture Farms and Farmers' Cooperative Demonstration Work, Seaman A. Knapp, 
Lake Charles, La.. Special Agent in Charge. 

Congressional Seed Distribution (Directed by Chief of Bureau); Lisle Morrison, Assistant 
in General Charge. 



r- r- n Editor, J. E. Rockwell. 

'to 26 1903 Chief Clerk, James E. .Tones. 



^'ora,' 



Farm Management Investigations. 
William J. Spillman, Agriculturist in Charge. 



Scientific Staff. — J. C. Beavers, G. A. Billings, D. A. Brodie, J. ^ Gates, J. S. Cotton, 
H. R. Cox, M. A. Crosby. L. G. Dodge, J. A. Drake, L. W. Ellis, J. W. Froley. C. L. 
Goodrich, David Griffiths. Byron Hunter, H. B. McClure, A. D. McNair, H. A. Miller, 
W. A. Peck. C. E. Quinn, C. B. Smith, S. M. Tracy, J. A. Warren, B. Youngblood. 

124 



.ETTER OF TRANSMITTAL. 



TT. S. DRPART:\rENT OF Agricitlture, 

Bureau of Plant Ixdustry, 

Office of the Chief, 
Washington, D. f'.. Decemhete, 1907. 
Sir: T have tho honor to transmit herewith, and to recommend 
for publication as Bulletin No. 124 of the series of this Bureau, a 
manuscript entitled "The Prickly Pear as a Farm Crop," by Dr. 
DaA'id Griffiths, which has been submitted by Prof. W. J. Spillman, 
Agriculturist in Charge of Farm Management Investigations, with 
a view to publication. 

This is the first. report based upon actual experiments dealing Avith 
the cultivation upon a field basis of any of the peculiar a]id interest- 
ing plants laiown as prickly pears. They have been utilized to a 
large extent in the economy of the stock business of southern Texas, 
but have never before been cultivated as a field crop in this country. 
The author desires to acknowledge his indebtedness in the conduct 
of these investigations to the cooperation of Mr. Alexander Sinclair, 
upon Avhose ranch the Avork is being carried on, and to his son, Mr. 
William Sinclair, Avho has so faithfully cared for the plantation. 
Respectfully, 

B. T. Galloavay, 

Chief of Bureau. 
Hon. James Wilson, 

Secretary of Agriculture. 

124 3 



CONTENTS. 



Page. 

Introduction 7 

Climatic conditions of tlie region 8 

Preparation of cuttings of priclvly pear 10 

Method of planting 12 

Time of year to plant 14 

Renewal of plantation 15 

Cultivation , . 15 

Time of harvesting •_ 10 

Method of harvesting 16 

Varieties to plant 18 

Cost of planting 19 

Spineless compared with spiny species 20 

Quantity of feed produced by jH'ickly pears 22 

Cultivation and noucultivation 24 

Some effects of cultivation 25 

Uses of the crop 20 

Prickly pear compared with sorghum 27 

Enemies of the prickly pear 28 

Summary — 31 

Description of plates 34 

Index 35 

124 5 



ILLUSTRATIONS 



rage- 

Plate I. Prickly pear experiments. Fig. 1. — Cultivated and nuculti- 

vated prickly pear. Fig. 2. — Covering cuttings with a plow. 

Fig. 3. — Cuttings distributed in furrow ready to be covered. 

Fig. 4. — Cuttings distributed on the surface of the ground, 

not to be covered 34 

II. I'rickly pear experiments. Fig. 1. — Cattle grazing singed 
prickly pear. Fig. 2. — Singeing prickly pear. Fig. 3. — Un- 
cultivated plantation twenty years old. Fig. 4. — Cultivated 

prickly pear two years old 34 

124 

6 



B. r. I.— 327. 



THE PRICKLY FEAR AS A FARM CROP. 



INTRODUCTION. 

No attempts have been made hitherto to cuHivate prickly pear as 
a resiihir crop in this country. The nearest approach to it was 
made by some of the old mission fathers of California, who im- 
ported cuttings, probably from Mexico, and planted them in hedges, 
where they served the double purpose of barriers against stock and 
as food for man. That they received any appreciable degree of 
cultivation, however, is very doubtful. They were probably grown 
in much the same manner that the so-called cultivated prickly pears 
are grown in Mexico to-day. 

An extended use has been made of the native crop at various times 
for the past fifty years or more in southern Texas, but it has mainly 
been spasmodic, lasting only until " the drought was broken," ex- 
cept for sheep and goats, which are fed on it regularly, and in the 
case of the few dairymen who have made it a practice to feed it for a 
portion of each year. In short, the prickly pear has been con- 
sidered an emergency feed, to be used only Avhen other feeds fail. 
Even enthusiastic pear feeders in Texas thought that the results to be 
obtained from planting and cultivating an experimental tract would 
only be " very interesting." There was little expectation that the 
plants would respond to cultivation as they have done. The facts 
presented in this paper, however, show that the prickly pear will 
produce, under proper cultural methods similar to those used for the 
common staple crops, yields of roughage superior to some of the 
standard agricultural crops of the region, especially when an otf 
3^ear occurs. It has proved itself under cultivation not only an 
emergency feed but an insurance against famine, as well as a plant 
which can be grown and depended upon regidarly as a farm crop. 

The investigations of this subject at the present time are very 
opportune indeed, because the demand for such a crop is not as great 
in southern Texas now as in a thickly settled region, giving ample 
time for growers to learn just the position that the crop should 
occupy in the economy of their operations. Land is still changing 

22052— Bui. 124— OS 2 7 



8 THE PRICKLY PEAR AS A FARM CROP. 

hands in southern Texas in 200-section blocks, and all of it has 
more or less prickly pear growing upon it. It is not to be expected 
that holders of such areas will be concerned with the culture of 
prickly pear any more than they will be concerned with the culture 
of any other crop, for they have plent}^ of pear growing wild in 
their pastures now. often more than they can possibly use. Settle- 
ment and subdivision of holdings are taking place very rapidly, 
however, throughout the region, and the time is not far distant 
when the whole counfry will be divided up into small holdings where 
the small farmer will depend upon a variety of crops and where use 
will be found for a crop like this which can withstand a protracted 
drought of two or three months or more without artificial irrigation. 

Indeed, many large communities now exist which need to grow 
sdme crop of this kind. In the vicinity of the larger cities dairymen 
have for years been in great need of roughage ' upon which they 
can depend, as well as succulent feed, which is not usually available 
during one-half of the year. In the vicinity of San Antonio, Tex., 
the feeding of the prickly pear has been so extensive during the past 
six years that the pastures have been practically depleted of it 
Avithin a radius of eight miles from the city. Still, the hauling of 
the crop such distances is doubtfully profitable, especially when it 
must now almost invariably be paid for. When it is remembered 
that a cow will eat in the neighborhood of 100 pounds a day, it will 
be readily understood that to haul pear such distances for feed is 
very burdensome. These dairymen could much better afford to turn 
some of their native brush pastures into cultivated fields of prickly 
pear, wherein they could feed the crop with no handling and be 
insured against a shortage of roughage. The conditions around San 
Antonio are practically duplicated near Laredo. 

Attention should be called here to the fact that this report applies 
to the experiments conducted at San Antonio only and that the terri- 
tory to which the experiments apply extends, roughly, from Houston 
to Del Rio and from Austin to Brow^nsville. Investigations along 
similar lines are being conducted in New Mexico, Arizona, California, 
and Florida, but it is not time to report upon them yet. 

CLIMATIC CONDITIONS OF THE BEGION. 

According to Bulletin Q. " Climatology of the United States," 
issued by the United States Weather Bureau, the mean annual pre- 
cipitation for the city of San Antonio for the past eighteen years 
has been 28.4 inches. The total amount for the driest year for the 
same period was IT). 9 inches, and the total for the wettest. year, 40.5. 
These figures are very important in the interpretation of these inves- 
tigations and show that the work is being done in a region of rela- 
tively high average annual rainfall. These tables do not, however, 

124 



CLIMATIC CONDITIONS OF THE REGION. 



9 



tell the whole story. It is necessary to study the monthly totals in 
order to appreciate the conditions of moisture prevailino-. The fol- 
lowing table is compiled from monthly totals of precipitation for 
the past ten years and shows in a striking way how irregular is the 
distribution of moisture: 

Table I. — Monthly totals of precipitation for Sian Antonio, Tex., for the ten years 
from 1897 to 1906, inclusive, in inches. 



Month. 


1897. 


1898. 


1899. 


1900. 


1901. 


1902. 


1903. 


1904. 


1905. 


1906. 


Monthly 
extremes. 


January.. 


1.59 

1.') 

1. 1)."-) 

1.84 

3.1.3 

2.19 

.28 

.40 

l.(il 

1. 3.') 

.43 

1.34 


0.46 
1.16 
1.47 
1.46 
1.06 
7.06 
2.24 
3,35 
1.32 
.03 
1.34 
1.54 


0.38 

.31 

*T. 

2.60 

2.22 

4.32 

2.85 

.00 

..57 

1.31 

1.70 

3.39 


5.42 

.34 
4.34 
9.11 
4.47 

.78 
2.24 
4.05 

.97 
2.94 
1.82 

.70 


0.41 

.71 

.54 

.59 

2.47 

1.86 

3.79 

.96 

4.20 

:S 

.,5 


0.70 

.55 

.12 

2.31 

3.14 

.02 

3.85 

.00 

5. .52 

2.54 

3.53 

2.51 


2.39 

7.88 

1.29 

1.74 

1.95 

4.75 

7. .52 

.20 

2.96 

1.61 

*T 

.82 


0.30 

.64 

.16 

3.25 

5. 93 

1.73 

3.50 

1.97 

7.74 

2.86 

.24 

1.06 


0.88 
1.62 
2.74 
6.08 
4.11 
6.01 
2.82 
.51 
1.80 
1.83 
2.63 
1.56 


0.29 
1.07 
1.29 
3.94 
.86 
.62 
4.34 
2.25 
1.74 
1.09 
1.33 
1.60 


0. 30 to 5. 42 

. 15 to 7. 88 


March ■ 

April 


*T. to 4.34 
..59 to 9. 11 


May 

June 

July 


1. 06 to 5. 93 
. 02 to 7. 06 
. 28 to 7. 52 




. 00 to 4. 05 




. 57 to 7. 47 


October 


. 03 to 2. 94 
*T. to 3. .53 




.15 to 3. 39 














*T.= 


trace 















With an equitable distribution of the rainfall there would be less 
demand for a crop whicli can withstand periods of drought. 

The column showing monthly extremes in the table above is most 
striking; only three months ha^•e a minimum of more than one-half 
inch. A glance at the columns of monthly totals will show nearly as 
striking variations for the seasons. Even this table does not tell the 
complete story. One must take into consideration the torrential 
character of the summer rains. A rainfall of 4 inches is not at all 
uncommon and may occur over a very local area. 

These are the moi.sture conditions especially adapted to the suc- 
cessful growth of prickly pear. Attention is called to this especially 
because of the apparently well-established idea in the popular mind 
that the plants will grow with little or no water — i. e., are adapted to 
any desert condition. On the contrary, they are adapted to grow 
where the rainfall is considerable but irregularly or periodically dis- 
tributed. These plants can not grow without water any more than 
any others, but they can get along for long periods without it on 
account of the large quantities which they store up in their succulent 
tis.sues. 

As regards temperature « we are concerned with this crop mainly 
in the minimum. The lowest temperature recorded by the Weather 

"The records are all compiled from the United States Weather Bureau 
records in the city of San Antonio, which are not perfectly satisfactory for our 
station, because it is not only 8 miles distant, but 70 feet above the ground, 
and consequently may not represent conditions where the plants grow within 
several degrees. These records, however, are the only ones available. 
124 



10 



THE PEICKLY PEAR AS A FARM CROP. 



Bureau for the San Antonio station is 4° F. in February. 1899, at 
which time, according to the best information obtainable, pear as 
well as the huisache {Acacia farnesiana) was badly frozen all over 
southern Texas. This is an unusual temperature and has occurred 
but once since the establishment of the station. The minimum in 
1905, the lowest since these investig-ations were begun, occurred on 
February 13. when a temperature of 13° F. was reached. Even this 
was considered an unusually cold season. At this time the native 
prickly pear appeared to be near the limit of its perfect endurance. 
A few plants in the open drooped a little, but no permanent injury 
was done, as they straightened up again in a short time. The mini- 
mum Fahrenheit readings recorded for San Antonio for ten consecu- 
tive years, beginning with 190G, are as follows: 24°, 13°, 22°, 19°, 26°, 
15°, 19°, 4°, 20°, 18°, 27°, and 11°. But even these temperatures are 
of short duration. It is seldom that seven days occur during an 
entire Avinter with an absolute minimum below 22° F. Winters are 
rather frequent when this temperature is not reached. 

Besides a minimum not lower than something like 12° F. a high 
average summer temperature is an advantage in the culture of 
prickl^y pear. During the ten years ending in 1903 there occurred 
on an average only four days a year with a maximum over 100° F. 
One year of this period had twelve days with a maximum above 100° 
F. and one year's maximum did not reach 100° F. The conditions 
in this respect are presented in the following table : " 

Table II. — Mnj-imum, minimum, and mean t r m peraturcM at San Antonio, Tex., 
for a period of eighteen and one-half years. 1888 to .1906, inelusive. 



Month. 



January. 
February 
March . . . 
April . . . 

May 

Juiie 



Mean. 


Maxi- 


Mini- 




mum. 


mum. 


op 


°F. 


°F. 


52 


82 


6 


55 


90 


4 


62 


97 


21 


70 


99 


35 


.75 


97 


44 


" 


103 


54 



Month. 



July...... 

August... 
September 
October. . . 
November 
December. 



Mean. 


Maxi- 




mum. 


op 


°F. 


83 


106 


83 


103 


78 


100 


70 


97 


60 


90 


55 


86 



Mini- 
mum. 



PREPARATION OF CUTTINGS OF PRICKLY PEAR. 

When these investigations were begun certain conventional for- 
mula^ for planting all species of cacti were more or less in vogue. 
These were found in the practices of horticulturists and in pub- 
lished reports, mainlj' of French investigators in northern Africa. 
These practices, briefly summarized, related mainly to propaga- 
tion from cuttings. It has been the custom among horticulturists, as 
well as the practice of the growers mentioned above, to prepare the 



" See also discussions of temperature on page 21. 



124 



PREPARATION OF CUTTINGS. 11 

cuttin<j!;8 some time, commonly two weeks, before planting them. In 
other words, the joints were somewhat wilted before being planted. 
This practice appears to be necessary under greenhouse conditions, 
and growers in northern Africa seem to be quite insistent upon the 
same practice for out-of-door culture. When planted under the 
humid conditions of the greenhouse, cuttings are much more likely 
to decay at the surface of the ground unless some of the moisture is 
evaporated before the cut surface is put in contact with moist earth. 

Prickly pear cuttings do not callous over and produce roots from 
the cambium and buds as do cuttings from ordinary trees and shrubs, 
but the cut surface heals over and roots are put forth from the 
areoles which contain the spines. It is important to bear this in 
mind in the propagation of the prickly pears. From the gi^eenhouse 
standpoint it is necessary that the cut surface be thoroughly dried 
before the cutting is set. 

Some attention was paid to this practice when the first plantings 
were made in the spring of lOO"). An attempt was made to prepare 
the cuttings at least forty-eight hours before they were planted, but 
it was not always done. Indeed, a considerable part of the planting 
occurred immediately after the cuttings were prepared. No bad ef- 
fect was observed from the practice followed, although some of the 
cuttings were planted during a very wet season. Since that time no 
attention has been paid to the wilting of the cuttings. 

The practice has been to use one- joint cuttings almost entirely for 
planting, and it is believed that this is the most advantageous, all 
things considered, for conmiercial practice. The favorite instrument 
for making the cuttings has been a hoe straightened out so that the 
blade is in a straight line with the handle. This is used much as a 
spade might be used for the same purpose. With this instrument the 
whole plant is cut up, as nearly as is convenient, into individual 
joints. Of course it is not always convenient or even possible to 
strike the union between the joints exactly, but this is approximated 
as closely as possible. Sometimes the instrument severs one side or 
the other, but this appears to make little difference, if any. 

When the 6 acres of ground were planted in the spring of 1907, it 
was done with the avowed purpose of performing the work as it was 
considered the practical farmer or dairyman would carry it on. It 
was the intention to get as practical a test as possible. The plants 
after being brought to the field were cut up into single joints mainly 
by the writer, but the hauling and distributing of the cuttings were 
done principally by negro and Mexican labor. The handling was 
done entirely with pitchforks, and the laborers were not cautioned at 
all about being careful not to injure the stock. As a result, practically 
every joint planted upon the entire 6 acres had from one to a half 

124 



12 THE PKICKLY PEAB AS A FARM CROP. 

dozen tine holes in it. In spite of this, it is certain that at least 99 
per cent of the cuttings grew. Indeed, the stand on all portions of 
the field was practically perfect. 

The above experience is cited to show that there is nothing im- 
practicable in our method of rough handling of the cuttings, not as 
a justification of such handling. The less injury the cuttings receive 
the better they will grow and the more vigorous plants will they 
make without doubt ; but it is by no means imperative that care to 
the sacrifice of speed in handling should be indulged in. The cut- 
tings will withstand quite rough treatment and still make good 
plants, but they should not be unnecessarily bruised or mangled. 

As has been stated, single-joint cuttings have been used as a rule. 
Occasionally when joints were very small two of them have been 
left attached. The whole plant has been used invariably. All the 
joints appear to grow equally well, but large, heavy joints two 
or more 3^ears old make much the best plants. Good plants are 
always obtained from old woody stems, often six or seven years old. ' 
These are also much less likely to be bruised and otherwise injured 
in handling than the younger growth. 

The ISIexican people who handle very small quantities commonly 
plant two and a half to three joint cuttings. Their object is to get 
fruit as early as possible. In the cultivation of their large tame 
forms they are not concerned with the stock-feed side of the question. 
They claim to get a good crop of fruit the third year from such cut- 
tings, while it would take five years to secure the same crop from 
single-joint cuttings. Good crops of fruit have been secured from 
single-joint cuttings of the native Opuntm lindheimeri in three years 
in southern Texas. The large tame forms of JNIexico are much larger 
plants, and it may consequently take them longer to come into bear- 
ing. Indeed, none of them grown from single-joint cuttings along- 
side of the Texas forms produced fruit in any quantity the third year. 

METHOD OF PLANTING. 

There are many points connected with the various operations of 
planting, cultivating, and handling of these plants that have not 
been fully demonstrated as yet. The best that can be done in con- 
nection with some of these processes is to give an account of the 
methods which have been used in these experiments. It is expected, 
of course, that thes6 will be improved upon as our experience in 
growing prickly pear becomes more extensive. 

When the cultural Avork was taken up a 6-foot row was decided 
upon as the most suitable. The distance between the cuttings in the 
row has been varied from 2 to 4 feet. Although plantings have been 
made for the purpose of determining which is the best distance, 

124 



METHOD OF PLANTING. 13 

still it is not possible to make ai\y definite recommendations at the 
present time any more than to say that close planting appears to be 
more productive in a general way than the more distant planting. 
So thoroughly did this appear to be the case in our first experiments 
that the entire G acres planted in the spring of 1907 had cuttings 
planted 2 feet apart, from center to center, in 6 or 8 foot rows. 

It is recommended to those who contemplate the cultivation of 
this crop for forage in southern Texas that 6-foot rows be adopted 
and that the cuttings be set 2 feet apart, from center to center, in 
the row. This will enable one to cultivate one way for two seasons, 
and the crop if harvested at the end of this time can be cultivated 
again for the succeeding two seasons, when the second crop is being 
grown, and so on indefinitely. It will be difficult to get a horse 
through 6-foot rows after the second year. It is (juite possible that 
further experience will demonstrate that other, distances will be 
more advantageous. It may be that 2 feet apart in the row will 
bring the plants too close together to produce the maximum yield, 
or that the red spider will prove less injurious when the plants are 
grown farther apart. These are questions which will require prac- 
tice to fully demonstrate. At present it appears that 2 by 6 feet 
is the proper distance. 

The stock planted has been secured from native pastures within a 
radius of 2 miles from the experiments. The plants cut olf at or 
near the ground have been loaded on wagons with pitchforks. 
Sometimes the larger plants have been cut up somewhat to facilitate 
handling. Wngonloads of stock of this kind have been distributed 
in the field in piles (see PI. I, fig. 3), which were subsequently pre- 
pared for planting by cutting the plants into individual joints with a 
hoe straightened upon its handle as described elsewhere. The cut- 
tings were then distributed with a pitchfork to the places where 
they were to grow. IMuch labor can be saved by a careful distribu- 
tion of the material so that it need not be carried far. 

Several methods of setting the cuttings have been tested. In 
the earlier plantings some were set on edge in furrows or in holes 
opened up with a shovel. This hand labor Avas very expensive 
and troublesome, and it was soon recognized that it would not do 
for commercial practice. In the last plantings made the cuttings 
w6re not touched by hand at all. A portion of the 6-acre tract 
planted in 1907 was laid out in rows by running a shallow furrow 
with a small walking plow. The cuttings were laid against the 
furrow, the base reaching nearlj^ to the bottom of the depression 
(PI. I, fig. 3). Another furrow was then turned in the same di- 
rection, throwing dirt over the bases of these joints, covering ap- 

124 



14 THE PEICKLY PEAR AS A FARM CROP. 

proximately one-half of them, sometimes more and sometimes less." 
(PI. I, fig. 2.) Another portion of the field was simply marked and 
the joints were laid on the surface of the ground at proper distances 
in the rows thus laid out. (PI. I, fig. 4.) 

When the ground is very dry, cloddy, or otherwise poorly pre- 
pared, it will be advantageous to partially cover tjie cuttings; but 
if the ground is well pulverized and in such condition that mois- 
ture will be brought to the surface by capillarity, just as good 
results will be secured by simply placing the cuttings on their 
sides in firm contact with the ground. Indeed, in the first plantings 
better plants were secured in this way than when the joints were 
planted on edge. 

Thei-e is good reason for this. Attention has been called to the fact 
that roots spring from the areoles or cushions of spines and spicules 
distril)uted regularly over the surface of the stems (joints). This 
statement is equally true of the new growth. It always springs from 
these areoles, but these spaces are always more numerous around the 
edges of the disk-like cuttings. When the cuttings are laid flat on the 
ground it is but a short time before unequal evaporation from the 
two surfaces causes them to. dish slightly. This will leave the areoles 
in the center of the lower surface in contact with the ground. They 
will form roots in a very short time. From any portion of the 
slightly upturned edge of the joint new growth may take place. In 
the case of joints buried 6 inches or more by the plow, or otherwise, 
the surface for ne.w growth is reduced at least by one-half and the 
base or foundation of the plant is also reduced, or, more properly, is 
much smaller than Avhen the cutting is laid flat and the whole edge is 
in position to send out new growth. 

It is very fortunate that the plants grow readily in this position, 
for planting in this way greatly reduces the labor involved. Usually 
all that is necessary is to drop the cutting into place from the fork. 
At other times it may be necessary to press it down with the foot or 
a slight pressure of the fork after it is in place. It should be borne 
in mind that the cuttings should be in contact with the ground. If 
they are held away from it an inch or so by clods, or even by the long, 
stout spines found in some of the varieties, the chances of their be- 
coming established are greatly reduced. Indeed, if none of the are- 
oles is in actual contact with moist earth the cuttingSvwill not grow. 

TIME OF YEAR TO PLANT, 

There are indeed few, if any, crops which have such a range of 
adaptability as regards the time at which they may be planted. Be- 

o Care must be taken not to cover the joints, for they will almost invariably 
rot if this is done. 
124 



CULTIVATION. 15 

ginniiiir with February, 1905, plantings were made between the first 
and tenth of each calendar month, except August, for the next twelve 
months, to determine, if possible, the most favorable season. No 
plantings were made in August because it was excessively dry and 
hot, similar to July, when cuttings failed to grow. .VU other plant- 
ings iXYQw as well at one season of the year as another. All of the 
plantings, except a part of those made in F'ebruary, were upon uncul- 
tivated ground, the joints being placed in a furrow and partially 
covered, as described elsewhere. This feature is again a decided 
advantage, for it enables the farmer to plant this crop at almost any 
time of the year. In other words, it can be done during a season 
when other farm operations are not pressing. There is little doubt 
tliat cuttings will grow even in July and August, provided those 
months happen to be sufficiently moist. 

RENEWAL OF PLANTATION. 

Little is known about the length of time during which a plantation 
will grow when repeatedly harvested in a systematic manner. Xo 
reliable data are available. The nearest approach is in the case of 
the planting made by Mr. D. M. Poor (PI. II, fig. H). This planta- 
tion, consisting of two-thirds of an acre, was established by Mr. Poor 
about 188;"). He laid off the gi'ound in rows 2 feet apart, with an 
ordinary tAvo-horse plow, in land which had been cleared of brush 
but never broken. Native pear was chopped up into one or two 
joint cuttings, distributed in the furrows, and subsequently partly 
covered with another furrow. The area has been used more or less 
for twenty years, but it has never been cultivated. It has never been 
harvested closely and certainly never systematically. 

A plantation well established and cultivated is good for an indefi- 
nite period, say fifteen or twenty years.' Should plants in various 
portions of the field die for some reason, it is a very simple matter to 
establish new ones when the crop is on the ground. All that is neces- 
sary is to cut off a joint and put it in the proper place flat on the 

ground. 

CULTIVATION. 

Upon the subject of cultivation little need be said. The ground to 
receive tlie cuttings should be well and deeply prepared, and subse- 
quent cultivation should probably be shallow, for the plants are shal- 
low rooted. There are no cultivators known which are exactly suited 
to this crop. In the experimental work described in these pages an 
ordinary one-horse spike-tooth cultivator has been employed. The 
()!)jection to this implement is that the framework is too large, inter- 
fering with the projecting branches of the plant, and also it is not 
easily regulated as to depth. Some tool of the nature of a one-horse 
22052— Bull. 124—08 3 



16 THE PEICKLY PEAR AS A FARM CROP. 

sweep which could be regulated so as not to go into the ground much 
more than 2 inches would be more serviceable. In the experimental 
plantation it has been the endeavor to cultivate just enough to 
keep down the weeds and prevent the ground from baking. To keep 
down the Aveeds thoroughly it has been necessary to go through the 
plantation occasionally with a hoe, knocking down such stray M^eeds 
as the cultivator did not reach. 

TIME OF HARVESTING. 

It is not the purpose of this paper to attempt to say how often it 
will be most profitable to harvest crops of prickly pear from estab- 
lished cultivated plantations. Experience in this matter, as in many 
others, has Ipeen too brief. All that will be attempted at the present 
time is to state what can be done with one definite plan of cropping. 

Prickly pear has been considered a slow-growing plant, and in- 
deed it is a sloAv grower under natural conditions, where it is obliged 
to compete with hardy grasses and other vegetation. In a previous 
publication ° the opinion has been expressed that it will take five 
years to produce a crop on uncultivated lands in the vicinity of Eagle 
Pass, Tex., while in the same publication estimates made by ranch- 
ers give the period as from two to three years. There appears to be 
no reason at present for changing the first estimate for uncultivated 
lands, while it has been demonstrated that a crop can be profitably 
harvested in two years in cultivated plantations. Whether a pro- 
portionately greater yield can be secured by allowing the plants to 
grow three or four years has not been determined, but a paying crop 
can be secured at the end of the second 3'ear, and probably can be 
utilized at the end of eighteen months to good advantage if plantings 
are made in February or March. The first harvesting done upon the 
experimental tract was two years after planting. As shown in an- 
other place, there was at that time more than sufficient roughage 
upon an acre to feed two cows for one year. 

But little fruit will be produced the first two years, but quite a 
large crop will usually be secured the third 3^ear. 

METHOD OF HARVESTING. 

The different methods of preparing prickly pear for the use of 
stock have been sufficiently discussed in other publications '' and 
need not be repeated here. 

In the singeing process economy depends largely upon the dispo- 
sition of the plants. In the case of natural growth much time is 

" Bulletin No. 74, Bureau of Plant Industry, " The Prickly Pear and Other 
Cacti as Food for Stock," 1905. 

^ Especially in Bulletin No. 74 of the Bureau of Plant Industry, pp. 12-20. 
124 



METHOD OF HARVESTING. 17 

consumed in walkinif from 'one plant to another, because the phmts 
are usually scattered over the field. Systematic plantinix economizes 
both time and fuel. 

In the harvestino; which has been done thus far upon the experi- 
mental plantations the torch lias been used on standing plants, and 
cattle have then been turned on to graze them (PL IT, figs. 1 and 2). 
Others have been cut doAvn and hauled out of the field. This work 
was done in the spring of 1907. In the autumn of the same season 
little, if any, difference could be noticed between the growth made by 
tlie plants harvested by the two methods. Those plants (grazed by 
the cattle, however, were left in a very ragged condition and conse- 
quently did not present so good an appearanc^. So far as growth is 
concerned, however, it must .be admitted that grazed pear was nearly, 
if not quite, as good as that which was cut down and hauled off. 

There are several methods of harvesting open to the grower, two 
of which have been mentioned here. Besides these methods the 
plants may be cut down before singeing, and, if desired, two rows 
may be cut into one center. The plants as they lie on the ground 
may then be singed. Again the plants may be singed as they stand in 
the row and then cut down, the cattle being allowed to graze them 
where they fall. It is quite possible that the best method is the last 
mentioned. 

The singeing is done by pointing the blast flame downward in the 
center of the plant, because in this Avay the maximum surface is 
covered at one time by the flame. Afterwards the outer joints will 
be touched by the blast. These processes can easily be regulated so 
as to interfere but very little with the stump which is to be left stand- 
ing. After the singeing the plants can be cut down and grazed Avhere 
they fall. This will avoid leaving the stems partially chcAved and 
macerated, in which condition they are more likely to decay and 
result in injury to subsequent growth. Of course the plants can be cut 
down before singeing, but the burning can not be done so advanta- 
geously after the plants are felled. When standing, both sides of the 
joints, which are in a more or less upright position, can be easily 
reached with the fl.ame. while when felled the lower side in contact 
with the ground can not be so easily singed. The two most impor- 
tant requirements are economy of time and fuel and protection of the 
stumps which are to produce future growth. These requirements 
should be borne in mind constantly. Any process which economizes 
time and fuel and does not injure the stem is the one to use. It 
seems to the writer that singeing and then cutting the plants down to 
be grazed Avhere they fall accomplishes this result best. 

Iii some instances in the experimental investigations the harvesting 
has been close, leaving nothing of the old plant but the original cut- 

124 



18 THE PRICKLY PEAR AS A FARM CROP. 

liii<>'. In other csises the harvestin"; has been done so as to leave all 
the joints directl}^ attached to the original cutting. The latter plan 
leaves a stump of two to four joints. If the plant was established 
from a cutting laid on the surface of the ground, a large base and a 
good surface for future growth to spring from will be secured. 
There is no doubt that a large stump of this kind is an advantage; 
neither is there much doubt that these old stumps will produce a much 
heavier yield for the second biennial crop than is jDroduced from the 
freshly established cuttings for the first crop. A considerably 
heavier growth was secured during the season of 1907 from plants 
having a stump of three or four joints from which to develop. 

VARIETIES TO PLANT. / 

In the southern Texas region there are several native varieties of 
prickly pear, but in each locality there is usuallj'- one variety which 
predominates. The very fact that it does predominate is fairly 
good proof of its superior value for that locality. 

In the vicinity of San 'Antonio the predominating variety is the 
typical form of Oinintia lindhelnieri Englm., and this is the one 
which is considered the best of all the forms for cultivation in this 
immediate locality. Befoi-e any plantings were made upon the ex- 
perimental tract a careful examination was made of the varieties in 
the neighborhood, and this one selected is the most promising. Subse- 
([uent results — for other varieties were also planted for comparison — 
confirmed the- first judgment. There is no (juestion that this is the 
most valuable of all the forms and species used. It has prominent 
and formidable spines, which turn white toward the end of the first 
season's growth, and abundant light golden spicules." Another 
native varietj'^ with a trifle darker color, less formidable spines, and 
brown spicules has also made nearl}?^ as good growth and a much 
heavier crop of fruit. This may prove valuable. From 150 to 200 
varieties ha\e been planted. On the whole, none is to be recom- 
mended above the spin}^ native just mentioned. Some of the vari- 
eties planted, however, have characters which are decidedly ad- 
vantageous. 

One cultivated spiny form secured farther south is very promising 
for breeding purposes. It has withstood the climate the first two 
winters very well, but should another winter like 1901-5 occur it is 
certain to suffer badly, for it was cut back very severely then in the 
locality where secured. The spines on this one are not as formidable 
as on the native form that is being grown, and the spicules are almost 



"See Bulletin No. 91, Bureau of Animal Industry, 1!)00, pp. 0-11, for furtlioi' 
notes on this species. 
12-J 



COST OP PLANTING. 19 

entirely absent on the joints. This variety has made a growth at the 
rate of not less than 55 tons to the a^re per annum dnrino; the past 
two years. 

The prospective planter should study the plants in his locality 
carefully before planting. He sliould select that form which makes 
the largest and most rapid, clean growth, and from that variety he 
should choose the most liealthy plants. Selection should be made 
first for vigor and second with reference to tlie habit of the plant. 
In southern Texas those forms growing most erect are to be pre- 
ferred. In no case should a low, prostrate, or sprangling form be 
used. As compact a growth as possible is desirable on accoimt of the 
greater ease with which such forms are singed and cultivated. An 
open-branching, low habit of growth renders the operation of culti- 
vation very difficult on account of the interference of the branches, 
with the animals and the machinery used in cultivation. 

COST OF PLANTING. 

During the spring of 1*.)()7 a careful ivcord was kept of the cost 
of planting G acres of prickly pear upon the experimental ])lots. 
Owing to the requirements of the farm, men could not be employed 
regularly for full daj's on the planting and preparation of the 
ground, but so far as the value of the record goes it is considered that 
nothing is lo.st, for tlie time has been kept in hours for man and team. 

The ground .selected had never. been plowed. It was in native 
grass, closely pastured for sevei'al 3'ears, and had been grubbed 
nearly clean of mescjuite and other brush years ago. The greater 
part of the plowing and harrowing was done at odd times between 
the 1st of January and the 1st of March. The season being very 
dry considerable difficulty was experienced in getting the soil well 
pulverized, and even the plowing was done with much difficulty. 

The stock used for planting was .secured from various local .sources, 
ranging from close by to 2 miles distant. The greater part of the 
stock, although it was practically all of the .same variety, was hauled 
from a neighboring ranch 2 miles away. Some Avas cut from a 
pasture about half a mile distant, and about four loads from a 
smaller experimental tract planted two years ago contiguous to the 
present field. 

The time employed in the va'rious planting operations, exclusive of 
the preparation of the ground (plowing and harrowing), was as 
follows : 

Hours. 

One man and team hauling stock (G acres) NH 

One man and team marking (6 acres) and covering (3 acres) 14 

One man distributing cuttings (G acres) "(4 

The laborers used in hauling were negroes and Mexicans, and the 
time was not employed to good advantage. It will be .seen froju the 

124 



20 THE PRICKLY PEAR AS A FARM CROP. 

above statement that the heaviest item of expense was for hanlinir 
the stock for planting, which ought to have been done, even under 
the disadvantages of distance, much cheaper. 

Assuming the vahie of a man and a team at $3 and a man at $1 a 
day of ten hours, the cost of planting an acre after the ground is 
prepared is a little less than $6. If it is assumed that the value of 
the preparation for planting is $3 an acre, then it costs about %^ an 
acre to get the cuttings planted. With good labor advantageously 
employed this expense could doubtless be reduced to $6 or $7 an 
acre, but even at $9 the operation is not expensive when it is consid- 
ered that a plantation is probably good for fifteen or twenty years 
and that subsequent planting or establishing plants is a simple matter 
when the material is on the ground and all that is necessary to estab- 
lish a new plant is to la}^ a joint in firm contact with the soil. 

SPINELESS COMPARED WITH SPINY SPECIES. 

Much emphasis has been placed of late, esj)ecially in popular writ- 
ings, upon the great advantages of spineless prickly pears. The 
spines of these plants leave an unpleasant memory. They are diffi- 
cult to handle, and the novice usually can not conceive how the 
plants can be utilized at all on account of their formidable armament. 
It naturally follows that if spineless forms can be substituted the last 
objection to them has been removed. They could then be handled with 
bare hands, and eaten as they grow b}' all kinds of live stock. So 
firmly is the " spineless cactus " idea established in the public mind 
that much talk has been made about establishing such forms, even on 
the deserts^ supplanting the native forms and producing an abun- 
dance of forage for live stock — this to be utilized without the singe- 
ing process to which the native spiny forms must be subjected. 

While such ideas are very interesting . and attractive, there are 
many practical considerations which nnist be taken into account. 
Of course, the expei'ience of the writer is as yet meager, these 
experiments having been carried on only about four years. How- 
ever, observation, together with three or four years' experimental 
evidence, while not conclusive, points strongly to certain conclusions 
which are not at all favorable to spineless forms for southern Texas, 
for the immediate future at least. * 

Thus far no spineless forms have been found which are hardy 
under the conditions existing at San Antonio. The Avriter has 
secured ten or twelve spineless forms from Mexico, and the Office 
of Seed and Plant Introduction of the Bureau of Plant Industry 
has imported for investigations as many more from Hawaii, south- 
ern Europe, and northern Africa, all of which have been planted 
and well cared for. All that are left of these spineless forms at the 

124 



SPINELESS COMPARED WITH SPINY SPECIES. 21 

present time are such individual plants as have been protected dur- 
ing the winter. There' are a feAv nearly spineless forms here and 
there in southern Texas, but so far as has been observed none of 
them are quite hardy. They live through one or two winters all 
right, but may be frozen down badly the third winter. The nearest 
approach to hardiness that has lieen seen is in the city of Laredo, 
Tex. There are here a few plants (nearly spineless) which often 
pass the winter uninjured, but they were fro/en to sucli an extent in 
February. 1004, that not less than one-half of the joints broke off. 
Even these are not hardy upon the plantation at San Antonio and 
probably would suffer nearly every winter at Laredo were the plants 
there not protected by surrounding buildings. 

Lack of hardiness I'cndei-s the spineless forms of no economic 
value at the present time in southern Texas. If they can not with- 
stand tlie winter temperature it is of course useless to plant them. 
But while this is true it is not at all improbable that these smooth 
forms may in time become very important and possibly entirely 
supplant in culture those forms which are now being grown. The 
bringing about of such a condition is, however, a long and tedious 
process which will involve years of breeding in which the farmer 
can usually take little or no part. Work along this line is now being 
conducted for the benefit and use of the future, but present resvlts 
must he secured from, spiny natives. Of course, in experimental 
work sight is not lost of the fact that economic conditions may 
change in the future so that it will be advisable to have spineless 
forms, but the whole question is one of production. If spineless 
forms which are hardy and which will produce moi-e feed than 
spiny species which are now being grown can be evolved thev will 
be valuable in proportion to the excess of feed which they will pro- 
duce. This is as yet a purely experimental field, but the spiny native 
varieties have been proved to be valuable. 

Aside from lack of hardiness, the spineless prickly pears have 
other disadvantages. Wherever grown they have to be fenced. It 
will be obviously impossible to grow them in uncultivated pastures, 
even in regions where they are hardy, for they would be grazed too 
closely, if not exterminated in a very short while. Fences are expen- 
sive. Unless the area planted to these forms were very large, Avhich 
it could not be for some time, a rabliit-proof fence would be re- 
quired. This sort of fence has been found necessary in order to 
protect the varietal plantings made by the Bureau of Plant Industry 
at San Antonio. Spineless forms would be severely injured by rab- 
bits, gophers, and rats. The latter often do considerable injury to 
the spiny native plants, but the spineless forms would suffer very 
severely. A planting of about a hundred cuttings of imported varie- 

124 



')9 



THE PRTCKLV PEAR AS A FARM CROP. 



lies, not all spineless, was completely destroyed in a fortnight by 
ral)l)its in sonthern Arizona two years ago. When a hirge acreage 
is j)Ianted the danger from these pests will not, of course, be so seri- 
ously felt, but it will be many years before any extended plantings of 
spineless forms can be made. There is not enough stock of spineless 
prickly pears in this country at the present time to plant 5 acres if it 
Avere all gathered into one place. 

A plantation of spineless prickly pear ,would not only have to be 
fenced, but stock could not be allowed to enter the field at any time 
of the year, for they woidd trample over the entire field, knocking 
down plants hither and 3'on and causing an unwarranted Avaste. 
All of the crop would have to be harvested, loaded on Avagons. and 
hauled to another lot to be feci. Tvemembering that 100 pounds a 
day Avill be eaten by an average coav, it Avill be seen that this 
procedure will mean considerable expense. In a 100-cow dairy 
it Avill mean the moving of 5 tons of material for feed each day, 
besides the removal of the manure. On the other hand, the spiny 
forms, singed and fed Avhere they stand, obviate this expensive han- 
dling and cause the manure for 100 coavs to be distributed each day 
on about one-fifteenth of an acre — by no means a small item in main- 
taining fertility. With spiny forms the number of plants fed or 
grazed each day is absolutely Avithin the control of the rancher, e\'en 
though stock is allowed in the field all of the time. 

So far as southern Texas is concerned the advantages of the spine- 
less and spiny prickly pears concerning Avhicli Ave have any knoAvl- 
eclge may be summed up as follows: 



Ad idiitdgcK! of sinin/ luitirc foruis. Advaiiidf/c.s of .s'/x'/ir/c.s.s- foiiiis. 

1. They are bjirdy. 1. They do not require sui.Lceing. 

2. They do not require fencinji. 
;>. They are injured but little hy wild 

animals. 

4. They require a niininnun of han- 
dling. 

n. They accomplish the distril)utif)n 
of the manure duriui; tlic day. 

QUANTITY OF FEED PRODUCED BY PRICKLY PEARS. 

Our knoAvledge of the yield of prickly pear, either under natural 
or cultivated conditions, is as yet quite imperfect, and the state- 
ments made herein Avith reference to yields are made Avith such 
reservation as is consistent with the meagerness of the evidence. 
HoAvever, it is believed that all computations in Avhatever manner 
made are exceedingly conservatiA'e, and miderestimate rather than 
overestimate in every case what may be secured from a cultivated 
crop of prickly pears. 

124 



QUANTITY OF FEED PRODUCED. 23 

The first plantings at San Antonio, and, indeed, the first attenipt 
ever made in this country to cidtivate this phmt as food for stock 
so far as the writer is aware, occurred in February, 1905. A plot 
of ground 41G feet long and 208 feet wide (2 acres) was secured 
under lease the preceding winter. Half of this area was plowed 
and put in a good state of cultivation, the other half being left in 
the condition in which it was found, i. e., in native sod, with all 
brush removed. One half of the cultivated portion (one-half acre) 
was reserved for varietal plantings and the other half was planted 
to three or four varieties of native species, the typical O^nintia Jind- 
heimeri predominating over all others. The whole area was laid off 
into G-foot rows, numbered 1 to 69, and all plantings have been 
made on this plan, variation being made in the distance apart of the 
plantings in the row only. 

Early in March, 1907, when the plantation was 2 years old, the 
first harvesting Avas made. Xo weights were obtained except on a 
small scale — too small, in fact, to make a reliable record, and conse- 
quently need not be reported upon here. In one instance 75 head of 
stock were turned in to graze off two i'oavs which had been singed. As 
nearly as could be estimated this number of cows got from this small 
area a full day's ration of roughage. There were some young cows 
among them, and some which did not eat pear as freel}^ as they should, 
but nevertheless they had been fed prickly pear regularly all the win- 
ter and were still receiving it daily. Accepting the above as the 
measure of the biennial production of forage of this plant under cul- 
tivation, it will readily be appreciated that at this rate 2 acres of this 
crop would, roughly, supply roughage for 75 cows for one month, 
and 25 acres would, roughly, supply their needs for one year, but as it 
took two years to grow this crop, on this basis it would require only 50 
acres to furnish rough feed for 75 cows continuously. It is recognized 
that this is a very crude and imperfect estimate of production, but it 
is, nevertheless, instructive wlien taken in connection with wliat the 
eye can see of the 2-37^ear-old crop shown in Plate II, figure 4. In or- 
der to put the matter very conservatively, suppose this area was in- 
creased 50 per cent : this would mean that 75 acres would furnish 75 
cows with continuous roughage. This is still a production equaled 
by that of few areas in the country. This quantity was produced 
during one very favorable and one very unfavorable season and 
probably represents about the average crop. 

More definite data upon production were secured early in October, 
1907, when the plantation was 31 months old. At this time two rows 
were selected near the east side of the native plantings on cultivated 
ground because they were thought to be typical of the half acre of 
the cultivated native Opuntia Undheimeri. These rows were har- 

124 



24 THE PRICKLY PEAR AS A FARM CROP, 

A'ested down to the original cutting and weighed. These tAvo rows, 
numbered 20 and 21 in the records, yielded 8,518 pounds. Rows 35 
and 36 were then harvested, and weighed in the same manner. Row 
36 was considered the poorest in the area. This was in part due to 
its being in close proximity to uncultivated ground and in lesser part 
to the ravages of the red spider. These rows were taken in order to 
be certain not to overestimate the production. These two rows 
yielded 7,269 pounds. On the four rows, therefore, there were pro- 
duced 15,787 pounds. The area occupied by them measures three 
twenty-sixths of an acre. The yield to the acre, consequently, was 
136,820 pounds, or 68f tons. On account of the time of the year at 
which the measurements were made it is rather difficult to reduce 
this thirty-one months' growth into yearly terms, but if it is assumed 
that three years' growth was secured an average yearly production of 
22^ tons of green, succulent forage is shown. 

This estimate of the average growth per annum of 224 tons is cer- 
tainly conservative. It is evident that the growing season is not 
closed the 1st of October, but, on the other hand, that a very decided 
increase will occur between that time and Februarj^ Again, the 
measurements were made at the close of a long dry season. It is quite 
certain that the growth for the remaining five months, together with 
the water absorption of the humid winter season, would be expressed 
by tons to the acre. Besides this growth of plant body, there was 
produced during the third growing season between 4 and 5 tons of 
fruit to the acre. This fruit is greatly relished by horses, cattle, 
sheep, and swine, and is harvested by them without assistance and 
without injury <to the plants. 

In feeding dairy cattle" at San Antonio it was found that a com- 
plete roughage ration of prickly pear consisted of about 140 pounds 
for each cow daily. In feeding steers for market at Encinal, Tex., an 
average of about 75 pounds was eaten daily by each steer. These 
figures would indicate that 100 pounds is about what the average ani- 
mal will eat in a day. But the yields previously stated show that 
sufficient roughage is grown here on an acre for about one and one- 
fourth animals. 

Any way it is figured, roughage of prickly pear for one mature 
bovine animal on an acre seems to be a very conservative estimate. 

CULTIVATION AND NONCTJLTIVATION. 

At the same time that estimates were made of the rate of growth 
on cultivated ground rows 37 and 38 were harvested. These were 

grown without cultivation. As stated elsewhere, a furrow was opened 

. , _» 

« Bulletin No. 91, Bureau of Animal Industry, 1906. 
124 



SOME EFFECTS OF CULTIVATION. 25 

in the native sod, the joints hiid ai>ainst the hmd side, and the dirt 
pulled back over their bases. The growth of pear on these tAvo rows 
in thirty-one months weighed 980 pounds. This is at the rate of 
8.49 tons to the acre. Eeducing this to terms of annual growth in the 
same manner as was done in the other case, we have 2.83 tons to i:ep- 
resent the growth per annum upon uncultivated ground; in other 
words, eight times as much forage Avas produced under cultivation. 
(See PI. I, fig. 1.) 

The method of planting insured the rooting of the cuttings prac- 
tically tlie same upon uncultivated as upon cultivated land. Practi- 
cally ever}'^ cutting in either situation rooted and grew through the 
period specified. , 

It should be noted that the plantation is under fence. The 
l)rickly pear upon the uncultivated ground, therefore, had to com- 
pete with its full complement of grass growth. It would have 
made a greater gain if the grasses were grazed off, as they commonly 
are in the native pastures of the region. The figures showing the 
relation of the production under the two conditions are conse- 
(|uently not comparable with what would take place in pasture- 
grown pear. Indeed, the growth in Mr. Sinclair's pastures just 
outside of our fence was very much greater than that upon our 
uncultivated area. This furnishes a very strong suggestion as to 
the cause of the increase of prickly pear in some sections of south- 
ern Texas since its occupation and settlement. Formerly, when 
grasses were not grazed so closely, they were stronger competitors of 
the prickly pears than they are now and Avere able to keep it in 
check. Overgrazing, coupled with the prevention of fires, is doubt- 
less responsible for the excessive growth of prickly pear in some 
sections of the region. On the other hand, the rapid increase of 
mesquite and other brush tends to check the growth of the pear, for 
it does not thrive in the shade. 

SOME EFFECTS OF CULTIVATION. 

During the year 1907 the drouglit from June to October 1 was 
much more pronounced than the average for this section. The 
prickly pear in the pastures surrounding the experimental plantings, 
as a consequence, was suffering considerably by the 1st of October. 
Nearly all of it was somewhat shriveled, and in a few instances the 
color had begun to change, showing the beginning of interference 
with metabolism. Upon the cultivated area, on the contrary, the 
long period with little precipitation had no apparent effect. All 
plants were thrifty and vigorous. It is believed that no particular 
nijury Avould have resulted if no rain had occurred for another three 
months. 

124 



26 THE PRICKLY PEAR AS A EARM CROP. 

The effect of cultivation upon the development of spines is natu- 
rally of some interest, and since the writer has often been questioned 
regarding the comparative spininess of cultivated and uncultivated 
plants, a few remarks upon the subject are made, with, however, no 
attempt at any generalization. In the case of the typical form of 
Ofuntia lindheimeri, which is being grown in the experiments, there 
is a decided increase in spininess under cultivation. Indeed, the en- 
tire plant looks somewhat different when cultivated; that is, a plant 
under favorable conditions is just as different from a plant growing 
under unfavorable conditions in this species as in the common culti- 
vated crops. A comparison of Plate II, figure 3, with Plate II, figure 
4, will tell better than words what the differences are. The first 
is a view of the Poor plantation, which, although planted originally, 
is in a practically native condition, for it was never cultivated. It 
will be readily seen that the spines are fewer by several fold upon the 
uncultivated plants. No quantitative measurements have ever been 
made, and consequently only general statements are possible at this 

time. 

USES OF THE CROP. 

A more or less complete discussion of the uses to which prickly 
pear is put will be found in Bulletin No. 74 of this series, and a 
further discussion of the value of the crop is contained in Bulletin 
No. i)l of the Bureau of Animal Industry of this Department. 

The crop appears especially adapted to dairy purposes because of 
the comparative ease with which the ration can be balanced by the 
addition of concentrates, which are used with all roughage in this 
region. The succulence appears to be a decided advantage, and of 
course can be obtained at any time of the year if the plants are 
grazed where standing or are harvested as fed. The importance of 
this can not be overestimated, for it applies to all seasons of the year, 
and oftentimes green feed for dair}^ cattle is as difficult to secure in 
the summer as in the winter. There is an impression in some sections 
that this feed can not be used after the new growth starts in the 
spring, but this is entirely disproved by the practices of several 
ranchers who. have used it at all seasons of the year with good re- 
sults. Of course there is a period during which the young growth 
will not be eaten on account of its being distasteful to animals,*^ and 
this growth will therefore be wasted at that time, but there is no 
season of the year when pear will not be readily eaten, especially 
if other feeds are short or dry. 

It is very probable that the crop can also be used successfully for 
the production of baby beef, as has been suggested Iw Mr. Sinclair, 

" See Bulletin No. 91, Bureau of Animal Industry, 1906, p. 17. 
124 



PRICKLY PEAR COMPARED WITH SORGHUM. 27 

Avho has fed pear with as great success as anyone in southern Texas. 
This region has been a favorite breeding ground for many years, and 
much beef is constantly prepared for market, a large part of which is 
accomplished by the use of prickly pear at some stage of its growth. 
The great draAvback in any beef production — especially in the pro- 
duction of baby beef — is a lack of continuity of feed. An abundance 
of pasture is to be had in some seasons, but in other seasons it is too 
short for the maintenance of a steady rapid growth. A roughage 
like this, therefore, which can be utilized at any season and is a sure 
crop, fills a gap not filled by any other. 

Prickly pear roughage is relished by nearly all kinds of live stock. 
No case is known of horses being fed on it, but other classes of .stock 
eat it readily. Cattle, sheep, goats, and swine relish it, and even 
chickens utilize it Avhen it is chopped for them. Hogs Avill eat even 
stumps and heavy joints that cattle leave. 

In short, it can be said that prickly pear is of vastly more impor- 
tance in southern Texas than is ordinarily appreciated. A crop 
which will produce twenty-odd tons of roughage to the acre per an- 
num with a degree of certainty not attained by any other, and this 
readily eaten by all classes of live stock, is not to be disregarded as 
an important farui crop even if it has been looked upon as some- 
thing of a nuisance in the past. 

PRICKLY PEAR COMPARED WITH SORGHUM. 

Upon another page it has been shown that 22f tons of prickly pear 
can be grown each year upon the grav^lly-black-waxy soils of the 
San Antonio region of Texas. Thfe main hay crop upon the ranch 
where the experiments are conducted has always been sorghum, and 
since the experiments were started this has been placed in a silo. In 
the season of 1906 about 1 ton of silage was secured to the acre, and 
in 1907 about 2^ tons. These are estimates made in the silo. 

In feeding tests upon the ranch in 1905 it was found that 6 pounds 
of prickly pear produced the same results in feeding dairy cattle as 
1 pound of dry sorghum hay." If 1 ton of hay is assumed to be 
equivalent in feeding value to 3 tons of silage, then the hay produc- 
tion froui sorghum has been on an average for the past two years 
only seven-twelfths of a ton to the acre per annum. This seven- 
twelfths of a ton of hay, assuming the relative value of sorghum hay 
to prickly pear to be as 6 to 1, is equivalent to only 3^ tons of pear. 
In other words, prickly pear has produced more than six times as 
much roughage during the past two years as sorghum. Of course, 
the A^eld of sorghum mentioned here is abnormally small, but sea- 
sons occur every now and then in this region when crops are short, 

" See Bulletin No. 91, Bureau of Animal Industry, 1906, p. 4. 
124 



28 THE PKICKLY PEAK AS A FAEM CROP. 

and while they may be assumed to be at the lowest point of produc- 
tion during these two years it is against these years of shortage that 
it is necessary to provide. 

ENEMIES OF THE PRICKLY PEAR 

There are many fungus and insect enemies of the prickly pear, 
but only one insect and one fungus need be considered in this place 
because the others have not thus far given cause for any appre- 
hension. 

The black-spot fungus {Perisporium wrightii) is first found as a 
soft, brownish area, usually more or less circular, on any portion of 
the joint. This soon becomes black and rotten, and later dries up when 
the ascogenous bodies appear upon the epidermis. Often there may 
be a dozen of these spots on a single joint, and these are approxi- 
mately one-half to 1 inch in diameter usually and extend clear 
through the joint. When but one or two occur the joint may re- 
cover, the tissue healing up around the diseased portion, when the 
dried diseased tissue falls out, leaving a notch or a clear circular 
opening through the joint. When the diseased spots are numerous, 
the plants are very much impoverished and the joints often drop off, 
the healing in this case occurring at the union between them. 

Fortunately this disease appears less prevalent upon plants under 
cultivation. In February, 1905, when the first plantings were made, 
one row, 208 feet long, was planted to very badly diseased pear in 
order to study the behavior of the disease. There are at present 
some diseased plants upon this row, and many of the cuttings failed 
to grow, but the vast majority of the plants have overcome the dis- 
ease quite perfectly. It is much more common on some varieties 
than on others, and the badly diseased material which was planted 
was discovered later to be of a different variety from that which it is 
recommended should be planted in the vicinity San Antonio. The 
typical form of Opuntia lindheimeri which is recommended is much 
less subject to this disease than some of the other native forms. It 
is a common disease in many species of prickly pear throughout the 
pear region from Texas to the city of Mexico. 

The only practical remedy is to feed the diseased plants and propa- 
gate from healthy stock only. At the present time it looks as though 
this method of handling would reduce the injury to a minimum. 
The cultivated area referred to, except where diseased pear was 
planted, is quite free from disease now. The stock was carefully 
selected, however, and there appears to be no disease on either the 
cultivated or uncultivated areas. 

The red spider {Tetimnychus opuntiae), on the contrary, is more 
serious upon cultivated than upon imcultivated land. These minute 

124 



ENEMIES OF THE PRICKLY PEAR, 29 

animals work around the areoles of spines and spicules first and 
g^radually cover the entire surface of the joint. After the}^ have 
worked on the pear, a yellowish or brownish dead callus forms over 
the entire surface. This cracks in places and there is often a consid- 
erable exudation of mucilage, which, although white at first, finally 
turns black. The plants are very much disfigured by this mite, 
but it can not be stated at present just how much real injury is done, 
for no plants have been observed which have been killed b}'^ it. 

It may be difficult for the uninitiated to recognize what the trouble 
with the plants really is, but after seeing it or having it pointed out 
it can not be overlooked, for the diseased condition is very character- 
istic. It is not so easy to find the mites, however, because they are 
very small and at times nearly, if not quite, absent. 

Just what tlieir habits are during the season has not been worked 
out. It is certain that they were abundant in March, 1907, and less 
abundant in the autumn of the same year. 

The Mexicans are very familiar with this diseased condition, but 
so far as known have not interpreted the cause. Attention has been 
called to it several times bj'^ Mexican ranchers, who deplored its 
presence and expressed the opinion that it might in time entirely 
destroy such forms as nopal amarillo, naranchado, chaveiio, and 
certain forms of joconoxtle. AVhile these fears express extreme 
views, there is no doubt that the red spider is a pest to be reckoned 
with. However, in Mexico, as in the United States, the greatest 
injury is done when plants are close together or growing intermin- 
gled with other shrub])ery. This crowding together of the plants 
is probabh' the cause of vthe large numbers of mites which developed 
in our cultivated experimental area. 

Experience is altogether too limited yet to permit much, if any- 
thing, to be said with any certainty about this injurious insect. 
A few observations, however, may be of interest. These, concisely 
tabulated, are as follows: 

(1) The disease occasioned by the red spider has long been known, 
but its cause has only recently been determined. 

(2) It has never been alarmingly abundant upon the uncultivated 
pear in southern Texas. 

(3) At the end of the second year a few red spiders appeared in 
our plantation. 

(4) During the third season these mites multiplied rapidly and did 
considerable injury to the older plantings. 

(5) All plants harvested in any manner whatsoever in the spring 
of 1907 were uninjured by the red spider during the season, although 
some of them were badly infested when harvested. 

124 



30 THE PEICKLY PEAR AS A FARM CROP. 

(6) No red sjDiders were found during the season on plantings 
made in the spring of 1907. 

(7) The red spider has been abundant upon thick phmtings only, 
and no injury has been done any of the plants except the natives 
thus far. 

(8) Red spiders are injurious only part of the year. In 1007 they 
were abundant in March. 

(9) Heavy rain washes the red spiders "off and they do not appear 
to regain possession for some time, but just how long has not been 
determined. 

(10) Prickly pear having red spiders on it is eaten as readil}^ by 
live stock as that which is not affected. 

The above observations indicate that the red spider can be kept in 
check by feeding such areas as are affected as they appear. The fact 
that the crowding together of the plants seems to increase the spread 
of the red spiders and the injury done may influence the method of 
planting. 

Another malady which is of very common occurrence can probably 
be discussed here as well as elsewhere, because it is connnonly looked 
upon as a disease. This occurs some time in the spring of every 
year at San Antonio. It is a condition in which the new joints of the 
plant drop off wdien about half grown. The recovery from its effects 
is very rapid, but of course the growth which drops off is lost. 

To illustrate the extent of this malady, a single case in which a 
quantitative estimate was made can be mentioned. About the mid- 
dle of May, 1905. a large plant harvested during the winter of 1903-4 
had just recovered from the effects of this malady. It had made a 
splendid growth the previous season and had started vigorously 
again when the joints began to drop off. At the time referred to 
most of the fallen joints were completely' dried. Fifty-two of them 
were lying at the base of the plant, while eleven more were par- 
tially injured. In spite of this, the plant had completely recovered 
and was then supporting, besides the eleven somewhat injured joints 
still clinging to it, fifty-eight perfectly sound and normal ones. 
AVhat proportion of the latter started after the falling of the first 
crop of joints can not be stated, but probably nearly all of them. 
This was a large, vigorous plant (second growth) from an old stump 
harvested several times, and probably represents an extreme case, but 
it is not uncommon for one-half to two-thirds of the first crop of 
joints to be lost in this way at San Antonio. 

The exact cause of this particular phenomenon has not been 
demonstrated, but it appears to be due to neither fungous nor insect 
enemy, but, on the contrary, to be purely climatic. Observations 
seem to indicate that the falling of the joints takes place some time 

124 



SUMMARY. 31 

after a cold and usually a moist spell of weather which occurs when 
the joints are about half grown and while they are thin and leathery, 
before they have begun to swell out into the normal shape of the 
mature joint. 

In 1907 this malady was at its height about April 27. At this time 
nearly all the season's growth on many species was destroyed, and 
in some none remained. In others about half fell off, while a very 
few varieties were uninjured. The native Opuntia Undheimeri was 
not much affected; possibly one-eighth of its joints were injured, 
but not more than this. All varieties recovered speedily, putting 
out new joints in a short time. No injury was done to the previous 
year's growth. 

While often a large part of the growth of a month or so in the 
spring is lost in this way. no apprehension is felt regarding the 
matter in respect to the yield. In fact, the 3^ields which are re- 
ported elsewhere in this paper have been produced each year in spite 

of this malad}^ 

SUMMARY. 

These experiments in planting prickly pear as a farm crop have 
been conducted in a region having a rainfall varying from 15^*'^ 
inches to 40^ inches a year, the average for the past eighteen years 
being 28f inches, but this rainfall is very unevenly distributed. 

The absolute minimum temperature for the locality is 4° F., but 
this is exceptionally low, having occurred but once in eighteen years. 
During the ten years ended in 1903 there was only one year which 
had seven days with a mininnun below 22° F., two years had none 
lower than 22° F., while the others had from one to six days during 
the year with a minimum temperature lower than 22° F. 

The plants are most advantageously grown from single- joint cut- 
tings, wdiich are easily prepared by cutting up all of a full-grown 
jjlant into single joints with a spud or spade. 

Plants should be established about 2 feet apart in 6-foot rows. 

When the ground is moist and w^ell prepared, cuttings can be 
distributed on the surface of the ground. When these conditions 
are not met the cuttings should be placed in a furrow and par- 
tially covered with another furrow. With care a sulky cultivator 
can be used for covering the joints. 

Planting may be done at any time of the year except during the 
hottest and driest part of summer. 

Cultivation shoidd be shallow and sufficiently frequent to keep 
down Aveeds and prevent excessive baking of the soil. 

Plants set in February can be harvested at any time of the year 
after twenty to twenty-four months. 



32 THE PRICKLY PEAE AS A FARM CROP. 

It is believed that it will be found advantageous in harvesting to 
singe the standing plants and then cut them down to be grazed. 
However, good results have been obtained without cutting. It is 
possible to singe after cutting, but it is a little more difficult and will 
probably be attended with more waste. 

It will be advantageous in harvesting to leave a stump of two to 
four joints rather than to harvest too closely. 

Those forms which are most vigorous and most free from disease 
should be selected for stock to plant. In the vicinity of San Antonio 
this is the t}q:)ical form of Opuntia Jindheimeri. 

The experimental plantation cost nearly $9 an acre, including all 
expenses, beginning with the breaking of the raw prairie and ending 
with the cuttings properly placed. With good labor and proper 
management this expense, it is believed, could be reduced to $6 or $7 
an acre. Even $9 per acre is low for a plantation that does not re- 
quire renewing for fifteen or twenty years. 

The spineless forms thus far grown (about twenty varieties) are 
practically useless under present conditions in Texas except for breed- 
ing purposes. 

A conservative estimate of the annual production of prickly pear 
under cultivation is 22* tons, or enough roughage for one bovine 
animal for a year from each acre of ground. This is to be harvested 
biennially. 

Cattle, sheep, goats, swine, and even chickens will eat the crop 
readily at any time of the year. 

Eight times as much growth of prickly pear has been secured 
under cultivation as was obtained without cultivation in ungrazed 
pastures. 

More than six times as much roughage (actual feeding value) has 
been secured during the past two j^ears from prickly pear as from 
sorghum. 

One fungous and one insect enemy of prickly pear of some im- 
portance are found, both of which may be controlled either by 
selection of stock or by methods of harvesting, or by both combined. 

The diseased condition known as dropping of joints is believed to 
be purely climatical. This, while costing a month's growth in the 
spring, is not looked upon with any apprehension. The yields given 
in this paper have been secured in spite of this injury. 

124 



PLATES. 



124 



33 



DESCRIPTION OF PLATES. 

Plate I. — Prickly pear experiments. Fiji. 1. — Cultivated and uncultivated 
prickly pear, showing relative si'owths. The first two'rows cultivated and 
thejfirst two rows uncultixated were planted in the same way and at the 
same time. The vegetation in the uncultivated area consists of native 
grasses and the broom weed (Amphcacharis (Iracunculoidcs). Fig. 2. — 
Covering the cuttings with a plow. Covered in this way they usually stand 
at an angle of about 45 degrees. Fig. 3. — Cuttings distributed in the furrow 
ready to be covered. When covered with a plow they stand at about the 
angle shown, but if a sulky cultivator is used to cover them they can be 
arranged nearly upright. In the distance will be seen piles of cuttin.j;s 
ready to be distributed. Fig. 4.— Cuttings distributed on tiie surface of the 
ground. These are not to be covered, but will grow readily in this position. 
This method of planting is to be recommended when the ground is 
thoroughly prepared and sufficiently moist. 

Plate II. — Prickly pear experiments. Fig. 1. — Cattle grazing singed prickly 
pear on the experimental plantation, March, 1!)07. Fig. 2. — Singeing 2-year- 
old pear upon the experimental plantation in Mai'ch, 1007. Fig. 8. — Uncul- 
tivated plantation 20 years old upon the Poor ranch, at San Antonio, Tex. 
This plantation bars been repeatedly harvested but never cultivated. Fig. 
4. — Cultivated prickly pear 2 years old upon the experimental plantation. 
Comjmre the aiipearance of the plants with the same variety shown in 
figure 3. 

124 

34 



Bui. 124, Bureau of Plant Industry, U. S. Dept. of Agriculture, 



Plate I. 




PRICKLY PEAR EXPERIMENTS. 



Fig. 1.— Cultivated and Uncultivated Prickly Pear. Fig. 2.— Covering Cuttings 
WITH A Plow. Fig. 3.— Cuttings Distributed in Furrow Ready to be Covered. 
Fig. 4.— Cuttings Distributed on the Surface of the Ground, not to be Cov- 
ered. 



Bui. 124, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate II. 




PRICKLY PEAR EXPERIMENTS. 

Fig. 1.— Cattle Grazing Singed Prickly Pear. Fig. 2.— Singeing Prickly Pear. 
Fig. 3-— Uncultivated Plantation Twenty Years Old. Fig. 4.— Cultivated 
Prickly Pear Two Years Old. 



INDEX. 



Page. 

Areoles, relation to propagation 11,14 

Beef, baby, use of priclvly pear in production 20 

Breeding hardy spineless varieties, possibilities 18,21 

Callus, cuttings 11 

Cattle, daily and annual consumption of i)rickly peai', estimates 8,22,23,24 

Chavefio, injury by red spiders 29 

Chickens, feeding on prickly pear 27 

Climate, prickly pear requirements 9-10 

Cold, effect on prickly pear 10 

Cost of planting 19-20,32 

Cows, ration of prickly pear 8,22,23,24 

Cultivation 15-10 

effects compared with noncultivation 24-20 

first attempt ^- 23 

Cuttings, preparation and handling 10-12 

Dairy pastures, availability of prickly pear 8 

use and adaptation of prickly pear 20 

Enemies of prickl.v pear 28-31 

Experimental planting. 1907. methods employed, etc 11, 12, 

13-14, 17, 18, J9, 20, 23-24 

Feed yield to the acre of cultivated prickly pear, estimates 22-24 

Fence requii'enients of spineless varieties 21 

Flavor, prickly pear, relation to use by stock 20, 27 

Freezing fatal to prickly pear, Texas '. 10 

Fruit, time of production 10 

Fungus, black-spot, description and remedy 28 

Goats, feeding on prickly pear 7,27 

Grass, effect on growth of prickly pear 25 

Greenhouse propagation, decay of cuttings, etc 11 

Harvesting, time and methods 10-18,32 

Hedges, use of prickly pear 7 

Hogs, feeding on prickly pear 27 

s:mplements for cutting, handling, and planting prickly pear 11,13,31 

Introduction to bulletin ■, 7-8 

Joconoxtle. in.iury by red spiders ' 29 

Joint-dropping disease, cause and effects 30-31,32 

Labor, negro and Mexican 19 

Mexico, method of planting prickly pear, etc 12 

Mites, red spiders injurious to prickly pear 13.28-30 

Naranchado, injury by red spiders 29 

Nopal amarillo, injury by red spiders 29 

124 35 



36 THE PRICKLY PEAR AS A FARM CROP. 

I'ase. 
Opuutia liudlieimeri, description, cbaracteristics, and rt'conmiendalions.^ 1!>, 

23, 26, 28, 32 

freedom from disease 28,31 

spininess increased under cultivation 26 

Pear, priclvly, climatic requirements S-10 

cultivation ir>-16 

and use, historical notes 7 

first attempt 23 

fungous and insect enemies 28-31 

feed produced . 22-24 

growth, rate . _ 16 

propagation and harvesting methods 10-18 

spineless species, advantages and disadvantages 20-22 

spiny species, advantages 22 

uses 26-27 

yield and value, comparison with sorghum 27-28 

under cultivation 22-26 

young growth distasteful to animals 26 

Perisporium wrightii, description and remedy 28 

Plantation, renewal 15 

Planting, cost 12-14, 31 

methods 12-14,31 

season 14-15 

Plants, selection for propagation 12 

setting, distance apart 13,31 

Plates, description 34 

Poor. D. M., planting of prickly pear 15 

Precipitation, San Antonio, Tex., monthly totals, 1807-1006 S-0, 31 

Prickly pear. See Pear, prickly. 

Propagation, areole as a factor 11,14 

distance between plants _^ 13,31 

methods and implements 10-14, .31 

suggestions for insuring growth of plants 14 

varieties recommended 18 

Rabbits injurious, especially to spineless varieties 21 

Rainfall, San Antonio, Tex., monthly totals, 1807-1006__ 8-0,31 

Ration, daily, prickly pear for cattle 8,22,23,24 

Red spiders injurious to prickly pear 13, 28-30 

Rodents injurious, especially to spineless varieties 21 

Roughage, value of drought-resistant crop 8 

San Antonio, Tex., climatic conditions : 8-10,31 

pastures, depletion of prickly pear 8 

Season for planting 14,31 

Setting plants in field, two methods 12-14,31 

Sheep, feeding on prickly pear 7.27 

Singeing process, directions 16-18,32 

Sorghum, yield compared with prickly pear — 27 

Spacing plants, proper distance 13,31 

Spiders, red, injurious - 13,28-30 

Spineless varieties, advantages and disadvantages 20-22 

hardy, breeding possibilities 18,21 

importations, experimental planting 20 

not hardy, useless in Texas 20, 32 

124 



INDEX. 37 

Page. 

Spines, development, effect of cultivation 26 

liiiidrance to propagation of plant 14 

Spiny varieties, advantages and disadvantages 20-22 

Summary of bulletin 31-32 

Swine, feeding on prickly pear 27 

Temperature, average, San Antonio, Tex., 1888-1906 9-10, 31 

Tetranychus opuntiae. injuries, observations 28-30 

Texas, climatic conditions 8-10 

forage cultivation, space between plants 13 

land sales and holdings 7-8 

need of drought-resistant crop for roughage S 

varieties preferred 19 

Varieties, care in selection 18-32 

preferred forms 19 

Yield to the acre under cultivation, estimates 16^ 22-24 

124 

o 



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LEJe'08 



